The present invention relates to an apparatus for cooling a blank mold in a glass receptacle forming machine, and more particularly to an apparatus for cooling a blank mold which can adjust the amount of cooling air to be supplied to a blank mold.
Most glass articles are manufactured by a process in which raw materials are converted by a furnace to molten glass that is then fed to a glass forming machine and formed into the glass articles.
In general, there is a known glass receptacle forming machine in which a gob of molten glass is fed to a mold for forming a parison (hereinafter referred to as blank mold) having a certain shape and then cooled to form a glass receptacle.
In the above glass receptacle forming machine, when molding glass, glass is cooled through the blank mold and the temperature of glass is lowered to the extent that glass is not deformed. The temperature of a gob is often not uniform in part and the coefficient of viscosity of glass is partially different. Therefore, in the glass receptacle forming machine in which air is blown into the blank mold, glass is not expanded uniformly, thereby affecting the glass receptacle wrongly in its thickness distribution. In order to rectify irregular temperature of the gob, glass portion of the high temperature is cooled to make glass molded by the blank mold uniform temperature distribution.
A conventional apparatus for cooling a blank mold is mounted on a main frame 1 through a base plate 3 as shown in FIGS. 16 and 17. The base plate 3 is fixed to the main frame 1 by bolts 5. A damper device 7 is provided below the base plate 3. The damper device 7 is provided with an air cylinder (not shown) having a tip end to which a damper 7a for opening or closing passage for cooling air is attached.
A spherical bearing 11 having an inner race and an outer race is interposed between the base plate 3 and a pipe 9a, the outer race of the spherical bearing 11 is secured to the base plate 3 and the inner race is secured to the pipe 9a. A pipe 9b is fitted with the outer periphery of the pipe 9a, the pipes 9a and 9b are rotatable and slidable with each other, thereby forming connecting conduit 13. Further, a spherical bearing 17 having an inner race and an outer race is interposed between a pipe 9c and a mold supporting device 15. The outer race of the spherical bearing 17 is secured to the mold supporting device 15, and the inner race thereof is secured to the pipe 9c. The pipe 9c and the pipe 9b are fixed by a ring pin 19 in such a manner that when operating in normal condition or replacing components with others, relative fixed position of these two pipes 9c and 9b can be changed.
The mold supporting device 15 has an upper portion to which a pipe 21a is fixed, a pipe 21b is fitted with an outer periphery of the pipe 21a. The pipe 21b is fixed to a plenum chamber 23. The plenum chamber 23 is positioned by a lock pin 27 above one of a plurality of the blank molds 25 supported by the mold supporting device 15. The plenum chamber 23 has cavities therein for temporarily storing cooling air. A cavity 23a and a cavity 23b are in communication with each other.
The plenum chamber 23 has a structure which is divided into a pair of components. In FIGS. 16 and 17, the blank molds 25 are supported at both sides thereof by the mold supporting device 15, the plenum chamber 23 is positioned by the lock pin 27 upside of the blank mold 25. In this type of cooling apparatus, the lock pin 27 is easily removed upward from the mold supporting device 15 so that the blank mold 25 is taken out from the mold supporting device 15.
The air cylinder constituting the damper device 7 is actuated by air pressure signal from a controlling device (not shown), whereby the damper 7a is opened and cooling air flows into the pipe 9a from the frame 1 as show by arrow A. This cooling air A flows into the plenum chamber 23 through each of pipes, and then flows into a plurality of passages 29 for cooling air provided in the blank mold 25 through the cavities 23a and 23b. The cooling air flows into the blank mold 25 from an inlet 29a of the passage 29 and cools the blank mold 25, and then is discharged from an outlet 29b to the outside of the apparatus or the atmosphere. The passages 29 for cooling air are generally formed on a circumferential wall of the blank mold 25 in such a manner that they are positioned on the same circle and at regular intervals and pierce through the wall in a vertical direction.
However, in the conventional cooling apparatus mentioned above, the amount of cooling air and pressure of cooling air supplied into the passages 29 of the blank mold cannot be freely adjusted to a desired value. That is, the amount of cooling air and pressure of cooling air supplied into each of a plurality of passages 29, 29 . . . 29 not only cannot be adjusted, if there are a plurality of the blank molds 25, 25 . . . 25, but the amount of cooling air and pressure of cooling air supplied into each of the blank molds 25 cannot be adjusted. If the amount of cooling air and pressure of cooling air cannot be adjusted, the thickness of the molded glass receptacle cannot be uniformly made to thus cause quality control of the glass receptacle to be difficult and troublesome.